Box elder bugs are common pests over much of the United States.
Adults are about 1/2 inch long.

They are bright red or black with narrow reddish lines on the back.

Box elder bugs feed principally by sucking juices from the box elder
tree, but are sometimes found on other plants.

They do very little damage to the trees they attack, but at certain
times of the year they can become a nuisance.
Box elder bugs develop by gradual metamorphosis, from egg, to nymph, then
to adult.

When box elder bugs build up to large populations and invade a home they
are usually pests only by their presence, although their piercing-sucking
mouthparts can sometimes puncture skin, causing slight irritation.

They seek shelter in protected places such as houses and other buildings,
cracks or crevices in walls, doors, under windows and around foundations,
particularly on south and west exposures.

Box elder bugs can come out even during the dead of winter when it is
cold outside and the sun is shining.

They will then emerge in the spring to seek out host trees on which
to feed and lay eggs.

How to get rid of box elder bugs

Once box elder bugs have become established in the home, there aren't a
lot of treatment options.
There are not a lot of recommended chemical measures at this point.
The easiest way to remove box elder bugs, once they are indoors, is with
a vacuum cleaner.

However, PREVENTION , is the best of all
choices . This is done during the Fall time.

Recommended residual insecticides

To help prevent box elder bugs, cluster flies, lady bugs and similar
pests from entering in the fall, outdoor, fast-acting synthetic pyrethroids
such as the ones listed below are recommended:

D-Fense will dry without a visible residue, while Cyper WP can be seen against darker surfaces. Both products will last 2-3 months on the surface once sprayed.

Spray around eaves, attic vents, windows, doors, under-fascia lips,
soffits, siding(including under lips) and any other possible points of
entry, concentrating on the south and the southwest sides .
Shady areas are less likely to attract box elder bugs.

Mechanical means of exclusion

Sealing box elder bugs out by caulking cracks and around utility service
openings, fixing broken window screens and door jams, plugging cracks
in the foundation or roof as well as similar exclusion-type activities
will help prevent the box elder bugs from entering in the first place.